BLOOD. 355 



Sp. gr. 



1-050 By my trial. 



1-0530 Richardson. 



1-0527 Haller, Phys. ii. 41. 



1-0570 Berzelius, Chimie, vii. 31. 



1-0510 Arterial blood. 1 -p. T -^ T i ro XT 

 i /^ftrt Tr 1.1 >Dr J.Davy, Journal of Science, No. 4. 

 1-0490 Venous blood. J 



1-0552 From temporal artery. ^ . 



1-0532 Venous blood. I Scudamore, Essay on Blood, 



1-0490 From jugular vein. ) p> 36 ' 

 1O560 Bullock's blood. Fourcroy, Ann. deChim. vii, 147. 

 1-0310 Calfs blood. Andrews, Records of Science, i. 33. 

 1-0530 Venous blood. Do. Ibid. 



1-0507 Mean. 



2. When blood is drawn from a living and healthy animal, it 

 is in a liquid state or nearly so. But it gradually coagulates, 

 and this coagulation takes place though the temperature of the 

 liquid be kept up, and whether it be exposed to or screened from 

 the action of the atmosphere. The blood of different animals, 

 and even of the same animal, at different times, shows a conside- 

 rable variation in the time that elapses after the blood is drawn 

 before it coagulates. This will appear from the following table, 

 for which we are indebted to Mr Thackrah : 



Blood of the Horse coagulates in from 2 to 15 minutes. 

 Ox, . . 2 to 10 



Dog, . to 3 



Sheep, hog, rabbit, J to 1-J 



Lamb, . . i to 1 



Fowls, . i to li 



Mice, ' . . in a moment. 



Fish, . in a moment.* 



3. When blood is viewed by a microscope while circulating 

 through the web of a frog's foot, or when newly drawn from a 

 living animal, it is found to consist of a yellow fluid, through which 

 a number of red globules are floating. These red globules ap- 

 pear to have been first noticed by Leewenhoek in the year 1674,f 

 He observed that they were heavier than the liquid in which they 

 floated. For soon after the blood is let out of the veins, the glo- 



* Hunter on the Blood, p. 211. f Phi l- Trans, ix. 23. 



